Process for the production of branched alkylbenzenes that uses a renewable carbon source

Abstract

A process for the production of alkylbenzenes in the presence of an aromatic feedstock and an olefinic stream produced from an ethanol feedstock, itself produced from a renewable source obtained from biomass, is described, with said process comprising at least: a) A stage for purification of said ethanol feedstock, b) A stage for dehydration of said purified ethanol feedstock, obtained from said stage a), into an effluent that is for the most part ethylene, c) At least one stage for separation of the water that is present in said effluent that is for the most part ethylene obtained from said stage b), d) A first stage for oligomerization of said effluent that is for the most part ethylene in the presence of at least one catalyst that comprises at least one element of group VIII, e) A second stage for oligomerization of at least some of the effluent that is obtained from said stage d) in the presence of at least one amorphous catalyst or at least one zeolitic catalyst, f) A stage for fractionation of the effluent that is obtained from said oligomerization stage e) in such a way as to recover at least one olefin-enriched olefinic stream that has a number of carbon atoms that is greater than or equal to 9, g) An alkylation stage of said olefinic stream that is obtained from said stage f) by at least one aromatic feedstock.

The invention claimed is: 
     
       1. Process for the production of at least one aromatic compound that belongs to the family of alkylbenzenes in the presence of at least one aromatic feedstock that comprises at least one compound that has a benzene core and at least one olefinic stream that is produced from an ethanol feedstock, itself produced from a renewable source that is obtained from the biomass, whereby said process comprises at least:
 a) A stage for purification of said ethanol feedstock, 
 b) A stage for dehydration of said purified ethanol feedstock, obtained from said stage a), into an effluent that is for the most part ethylene, comprising water, whereby said stage operates in the presence of at least one amorphous acid catalyst or at least one zeolitic acid catalyst, 
 c) At least one stage for separation of the water that is present in said effluent that is for the most part ethylene obtained from said stage b), 
 d) A first stage for oligomerization of said effluent that is for the most part ethylene, obtained from said stage c), in the presence of at least one catalyst that comprises at least one element of group VIII for producing at least one light olefinic effluent that comprises at least 50% by weight, relative to the total mass of the olefins that are contained in said light olefinic effluent, of olefins that have a number of carbon atoms that is greater than or equal to 4, 
 e) A second stage for oligomerization of at least some of the effluent that is obtained from said stage d) in the presence of at least one amorphous catalyst or at least one zeolitic catalyst for producing at least one olefinic effluent that comprises at least 50% by weight, relative to the total mass of the olefins that are contained in said olefinic effluent, of olefins that have a number of carbon atoms that is greater than or equal to 8, 
 f) At least one stage for fractionation of the effluent that is obtained from said oligomerization stage e) in such a way as to recover at least one olefin-enriched olefinic stream that has a number of carbon atoms that is greater than or equal to 9, 
 g) An alkylation stage of said olefinic stream that is obtained from said stage f) by at least one aromatic feedstock that comprises at least one compound that has a benzene core. 
 
     
     
       2. Process for production according to  claim 1 , such that said dehydration stage b) operates in the presence of a zeolitic acid catalyst that comprises at least one zeolite that has a structural type that is selected from among the following structural types: MFI, FAU, MOR, FER and BEA. 
     
     
       3. Process for production according to  claim 1 , such that said effluent that is for the most part ethylene produced by said stage b) comprises at least 95% by weight of ethylene relative to the total mass of the carbon-containing compounds that are formed and present in said effluent. 
     
     
       4. Process for production according to  claim 1 , such that said dehydration stage is implemented in at least one reactor that operates in a fixed bed, a moving bed, or a fluidized bed. 
     
     
       5. Process for production according to  claim 1 , such that said separation stage is followed by at least one stage for purification of said effluent that is for the most part ethylene from which water was eliminated in advance. 
     
     
       6. Process for production according to  claim 1 , such that the content of water that is present in the effluent, obtained from said stage c) and sent into said first oligomerization stage d), is between 0 and 1,000 ppm. 
     
     
       7. Process for production according to  claim 1 , such that among the olefins that have a number of carbon atoms that is greater than or equal to 4 and that are present in said light olefinic effluent obtained from said stage d), the C4-C8 olefins are in the majority relative to the C9+ olefins. 
     
     
       8. Process for production according to  claim 1 , such that said first oligomerization stage is implemented by heterogeneous catalysis in the presence of at least one catalyst that comprises at least one element of group VIII and at least one porous oxide refractory substrate. 
     
     
       9. Process for production according to  claim 1 , such that said first oligomerization stage is implemented by homogeneous catalysis in the presence of at least one homogeneous catalyst that contains at least one metal precursor that comprises at least one metal of group VIII that is selected from among nickel and iron. 
     
     
       10. Process for production according to  claim 1 , such that at least one separation stage is implemented between the first oligomerization stage d) and the second oligomerization stage e). 
     
     
       11. Process for production according to  claim 1 , such that said olefinic stream that is obtained at the end of said stage f) comprises olefins that have 10 to 14 carbon atoms per molecule. 
     
     
       12. Process for production according to  claim 1 , such that said olefinic stream that is obtained at the end of said stage f) comprises at least 90% by weight of olefins that have a number of carbon atoms that is greater than or equal to 9. 
     
     
       13. Process for production according to  claim 1 , such that said alkylation stage g) is implemented in at least one reactor that operates either by homogeneous catalysis or by heterogeneous catalysis. 
     
     
       14. Process for production according to  claim 1 , such that said aromatic compound that belongs to the family of alkylbenzenes is an aromatic compound whose benzene core carries at least one saturated and branched alkyl chain that has at least 9 carbon atoms. 
     
     
       15. Process for production according to  claim 14 , such that said saturated alkyl chain carries 1 to 5 branches.